Risks: Extra Sleep Is Found to Lower a Heart Risk

One more reason for getting a good night’s sleep: sleeping an extra hour a night may help control coronary artery calcification, a major risk factor for heart disease.

The effect, reported in the Dec. 24 issue of The Journal of the American Medical Association, was so strong that the researchers concluded that one extra hour of sleep was the equivalent of lowering systolic blood pressure to a normal 120 from 136.

“While this is an intriguing new finding, this one study does not by itself establish a causal relationship,” said Diane Lauderdale, the senior author and an associate professor of epidemiology at the University of Chicago. “It may be that there is some other factor that influences how much people sleep and independently influences calcification.”

The scientists followed 495 healthy men and women, ages 35 to 47, for five years, measuring their sleep patterns with electronic monitoring devices and examining their arteries with CT scans.

Over all, the group averaged 6.1 hours of sleep a night. But after controlling for age, blood pressure, cholesterol and other factors, those who averaged an extra hour’s sleep every night reduced their risk of calcification by about one-third.

A version of this article appears in print on , on Page D6 of the New York edition with the headline: Extra Sleep Is Found to Lower a Heart Risk. Order Reprints|Today's Paper|Subscribe